JPH06341799A - C-value deciding method for rodlike charge - Google Patents

Abstract

PURPOSE:To decide a safe c-value in which an accident of scattered debris by applying Hauzeur's formula based originally on a one point concentrated charge system to reality of rodlike charge in a perforated blasting. CONSTITUTION:An entire charge length, i.e., a chargeable perforated hole length is uniformly finely divided to set many one-point charge unit blocks, a charge amount per each unit block is divided by a fracture baserock volume per unit block to calculate the c-value per each block, the c-value per each unit block is integrated from a lowermost part to a desired rodlike charge length, and the c-value of the rodlike charge length is decided.

Description

Detailed Description of the Invention

[0001]

This invention is based on Hauser's formula, which is based on the condition of ex-rice

[Mathematical formula-see original document] relates to a method for rationally determining the c value, that is, the blasting coefficient or the fractured rock unit, so as to be able to correspond to the current situation of charging rod-shaped along the drilling length in actual blasting.

[0002]

2. Description of the Related Art As shown in FIG.
g), the blast coefficient or fracture rock mass unit is c, the minimum resistance line length is W (m), and the minimum resistance line length W (m) is set equal to the fracture radius R (m) in the free planes G and L. And Hauser's formula if the charge is assumed to be concentrated

It is well known that the following equation is established.

Therefore, this

Transforming [Formula 1] to obtain the c value,

[Equation 2]

On the other hand, the volume of fractured rock V (m ³ ) in the above case is calculated from the formula for determining the volume of a cone.

[Mathematical formula-see original document] Since W = R and R is replaced by W,

[Equation 4] Therefore,

[Formula 4]

Substituting into Equation 2, the c value is

It can also be displayed as:

As is clear from these relational expressions, the blast coefficient c value is

The fractured rock volume V shown by

It is understood that both are related to and have an influence on the minimum resistance wire length W shown by the following equation.

[0006]

[Problems to be Solved by the Invention] However, the Hauser's formula

As described above, the expression (1) is established on the assumption that the charge is concentrated at one point, that is, the one-point concentrated charge method is premised, whereas the charge in the actual blasting work A rod-shaped charge having an arbitrary volume along the length direction, that is, a rod-shaped charge method is a reality, and depending on the setting conditions, there is a large difference in the c value between the two, and the Hauser's formula is used. Although the calculated c-value calculated from the above is recognized as a safe value that does not cause flying stones, flying stones may occur during actual blasting, sometimes leading to personal injury, so the actual c-value is dangerous. There are cases.

For example, as shown in FIG. 2, perforation length H = 1.
charging length l = 1 m, perforation diameter r = 0.025 m,
When the volume of destroyed rock mass V is 1 m ³ and the specific gravity of explosive is 0.83, the amount of charge L is 0.41 kg. Therefore, the theoretical value of c obtained from the relationship with the volume of broken rock mass is:

0.41 is calculated using the following equation, and if it is this c value, it is considered to be safe.

On the other hand, on the other hand, the theoretical value of c obtained from the relation with the minimum resistance line W is

Since the denominator becomes 0 by using the following equation, it becomes infinite.

In the above case, considering which of the theoretical values of c is more accurate and the actual value of c under the set conditions, this situation shows that for a perforation length of 1 m, the free surface G,
Since it is fully charged until reaching L and the state of the filling length, that is, the minimum resistance wire length W = 0, at the time of blasting, a dangerous stepping stone like a fireworks launch occurs, and therefore at least

It is understood that the theoretical value of c using Eq.

The object of the present invention is, in punching and blasting, the Hauser's formula, which is originally based on the single-point concentrated charging method.

[Equation 1] is to be applied to the reality of rod-shaped charge, and to provide a method for rationally determining and applying a safe c value that does not cause a risk of a flying stone accident.

[0011]

The present invention is based on the recognition and handling of rod-shaped charge as a cumulative aggregate of one-point concentrated charge, and in order to achieve this, the rod-shaped charge length l (m)
Is divided by a perforation diameter r (mm) or a numerical value close thereto, and is divided evenly, and a large number of single-point charging unit blocks are provisionally provided.
That is, for example, if the product of the amount of charge L 1 per 1 m and the length of charge ₁ is the total amount of charge L, and the total amount of charge L is divided by the unit block division number l / r, the quotient is obtained. The charge amount Ln per unit block. Then, the amount of charge L _n = constant value per unit block is set to the cube of the minimum resistance wire length W ₁ to _n per unit block, that is, the volume of broken rock mass V _l to _n = W _l per unit block. if divided by ³ ~W _n ^3, c values _l ~ _n per unit block is calculated. Further, the c values _l to _n per unit block are measured from the lowermost part to the desired rod-shaped charge length.

Summing up by the following equation, the cumulative c value does not fall outside the rational c value in the desired rod-shaped charge length l _n = perforation length H−minimum resistance wire length W _n .

In the above case, the total charge length l _n ≤ perforation length H
(M).

In the present invention, the minimum resistance wire length W (m) and the fracture radius R (m) on the free surface are set equal to each other as a precondition of the Hauser's formula. Therefore, the fracture bedrock volume V = W ³ In principle, However, it is possible to set the minimum resistance wire length W (m) and the fracture radius R (m) on the free surface unequal, and in that case, set the fractured rock volume V = W · R ² . .

[0014]

When the method according to the present invention is used, Hauser's formula, which is well known as a single-point concentrated system, is used.

Transformation of [Equation 1]

The c value of the rod-shaped charge can be accurately obtained by using the equation (2).

[0015]

EXAMPLE As shown in FIG. 3, perforation length H = 1.2 m, fracture radius on free surface or perforation interval length R = 1.02 m,
In the case of blasting with a total charge length l = 1.02 m and a hole diameter r = 0.03 m, if the charge amount per 1 m is 0.58 kg / m, the value of the total charge amount L is Quantity L = total charge length l x
Amount of charge per 1 meter = 1.02 x 0.58 = 0.5916
It is kg. Therefore, perforation length 1.02 m is perforation diameter 0.0
If it is equally divided by 3 m, 34 blocks are formed, and the amount of charge L _n = 0.0174 kg per block,
The minimum resistance wire length W in each block, the c value in each block = L _n / W ³ , and their cumulative c value is

And the values in each block are shown in Table 1.

In Table 1, for example, considering the specifications of perforation blasting up to the thirteenth block, the length of charge l = 13 × 0.03 m = 0.39 m, the amount of charge L ₁₃ = 13 x 0.0174 kg = 0.2262
kg Minimum resistance wire length W ₁₃ = 0.63 m Broken rock volume V = W ³ = 0.25 m ³ , C ₁₃ = L _n / w ³ = 0.0174 / 0.25 = 0.0
696, and the cumulative c value is 0.4956≈0.5.

Table 2 is a list of minimum resistance wire lengths W in which the cumulative c-values for various drilling diameters r (mm) and drilling lengths H (m) are displayed in the range of 0.05 to 0.70. , Which is shown in the figure is shown in FIG.

In the above-mentioned embodiment, the total amount of charge 1 is set to the perforation length H.
It is also possible to set equal to or shorter than the perforation length H.

Further, in the above-mentioned embodiment, the unit length for dividing the total charge length 1 is the perforation diameter r, but it is possible to set other numerical values close to it.

Further, in the above-described embodiment, the minimum resistance wire length W
And the fracture radius R on the free surface were set equal,
It is also possible to set them unequal.

[0021]

INDUSTRIAL APPLICABILITY The present invention is originally based on Hauser's formula for blasting and blasting, which is based on a single-point concentrated charge.

[Equation 1] is that it was difficult to derive the correct amount of charge L and the fractured rock unit (blast coefficient) c during rod-shaped charge, but the charge length was subdivided into blocks. Since the above problem was solved by tentatively establishing the situation of point-concentrated charge and then obtaining the c value by accumulating each of those c values until reaching the desired charge length, The danger of stepping stones accidents caused by Mari has been eliminated.

[Brief description of drawings]

[Figure 1] Hauser's formula

Explanatory diagram of [Equation 1],

Figure 2: Hauser's official variant

Explanatory diagram of [Equation 2],

FIG. 3 is an explanatory diagram of a c-value determination method according to the present invention,

[Figure 4]

It is a figure which shows the relationship of the cumulative c value (vertical axis) and minimum resistance wire length W (horizontal axis) in various specifications shown in [Table 2]. H Perforation length r Perforation diameter R Fracture radius or perforation interval length l Total charge length G, L Free surface W Minimum resistance line length V Fracture bed volume L Charge amount

[Equation 1] L = c · W ³

## EQU2 ## c = L / W ³

(3) V = 1 / 3πR ² W

(4) V = W ³

[Expression 5] c = L / V

[Equation 6]

[Table 1]

[Table 2]

Claims (4)

[Claims] 1. In the perforation blasting with a rod-shaped charge, the total length of the charge, that is, the perforable length of the charge, is equally subdivided, and a large number of single-point charge unit blocks are provisionally provided, and a minimum resistance wire length is set. The fracture radius on the free surface is set equal, and the amount of charge per unit block is divided by the cube of the corresponding minimum resistance line length per unit block, that is, the volume of fractured rock mass per unit block. Then, the c-value for each unit block is calculated, and the c-value for each unit block is accumulated from the bottom to the desired rod-shaped charge length, and the c-value for the rod-shaped charge length is calculated. A method for determining a c-value in a rod-shaped charge, characterized in that 2. The method for determining the c value in rod-shaped charge according to claim 1, wherein the total length of the charge is set equal to the length of the perforation or is set shorter than the length of the perforation. 3. The unit for dividing the total charge length is set to a hole diameter or a value close thereto.
A method for determining a c-value in the rod-shaped charge described. 4. When the minimum resistance line and the fracture radius on the free surface are set to be unequal, the fracture bedrock volume is set as the product of the square of the fracture radius and the minimum resistance line length. The method for determining the c value in the rod-shaped charge according to claim 1.